| This could be a good thing, You may be building up your strength an dexterity from all those hours of practice/exercise, just like jogging or stretching when outta shape, you over exert and stretch muscles and feel weak when actually you are building up and strengthening. Now the bad thing is this could be an indication of the beginning of carpal tunnel syndrome, Using the same repetitive movement continuously over long periods of time and not doing any other movement in the area can cause this. It happens in typists,drummers, carpenters and and many people who make the same repititions over months and years, I know I have had the beginning of CTS and began doing alternate exercises with my wrists and it cleared things up-Per Doctors orders. Have you been playing like this for years and is this an all of a sudden syptom? If so I would be careful and if symptoms worsen I.E. pain in hand between thumb and index finger, numbness, tingling etc. have it checked out. This is just my own experience as a result of namely typing and my knowledge of this from others I.E. Guiturds, drummers, typists. etc. If you are just overexerting, what the heck go for it, you can be building up those bass jammin areas of your hands. But remember!!! Continuous repetitve movement without any other type of movement or exercise in you wrists can be harmful, I hope this helps. | 
